SAKURA-Pigma Pen Set. This pen set is ideal for all kinds of sketching, inking, and illustrating projects. The archival quality ink is waterproof, chemical resistant, fade resistant, bleed free, quick drying, and pH neutral. There are eight pens each with a different tip size or style (.2mm, .25mm, .3mm, .35mm, .45mm, .5mm, brush, and graphic), all have black ink. This package contains one set of eight pens. Acid free. Conforms to ASTM D-4236.